Lifting-jack.



No. 688,012. Patented Dec. 3, I90l.

n. s. BERGER.

LIFTING JACK.

(Application filed Sept. 9, 1901.)

(No Model.)

flVeJLivrk 1%;5'. Berger.

UNlED STATES PATENT OFFICE.

ROBERT S. BERGER, OF GRANERE, PENNSYLVANIA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 688,012, dated December 3, 1901.

Application filed September 9,1901. Serial No. 74,796. (No model.) 7

To all whom it may concern.-

Be it known that 1, ROBERT S. BERGER, a citizen of the United States, residing at Granere, in the county of McKean and State of Pennsylvania, have invented a certain new and useful Lifting-Jack, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to lifting-jacks of that type in which one or more screws are employed in connection with an operatinglever, whereby the lifting efiect is produced.

The object of the present invention is to provide a screw-jack embodying a plurality of screws nested one within the other and combined with a supporting-base and casing and an operating-lever, the screws being so related to each other and combined with a clamp-collar that a differential feed may be obtained by the employment of 'one or both of the screws. The change from single to double feed may be quickly effected, thus adapting the jack to a variety of uses.

With the above and other objects in view,

the nature of which will appear more fully as the description proceeds, the invention consists in the novel construction, combination, and arrangement of parts hereinafter fully described, illustrated, and claimed.

In the accompanying drawings, Figure 1 is a side elevation of a screw-jack constructed in accordance with the present invention, showing the cap partially elevated. Fig. 2 is a vertical longitudinal section through the same, taken at right angles to Fig. 1. Fig. 3 is a horizontal section taken adjacent to the ratchet-collar, showing the latter in elevation. Fig. 4 is a detail plan view of the clamping-collar. Fig. 5 is a diametrical section through the same.

Similar numerals of reference designate corresponding parts throughout the views.

Referring to the drawings, 1 designates a cylindrical casing in which the screws are housed when lowered, the lower portion of said casing being expanded in size to form a supporting-base 2. The upper portion of the casing 1 is internally screw-threaded, as at 3, to receive and engage the exteriorly-threaded lower screw 4. The lower or main screw 4 has its upper portion internally threaded, as shown at 5, to receive the upper or inner screw 6. The outer or lower screw is tubular, and the inner or upper screw may be either solid or tubular, being shown for convenience as solid. Adjacent toits upper end the inner screw 6 is provided with a head 7, from which extend radially a series of lugs 8, provided with openings 9 to receive a suitable bar, rod, or lever, by means of which the upper screw maybe turned within the lower screw. The screw 6 is also extended above the head 7 to form a journal 10, around which is revolubly fitted a cap or rest 11, which is provided with a screw-threaded opening for the reception of a thumb-screw 12, the inner end of which is adapted to enter an annular groove 13 in the journal portion 10 of the screw. The screw 12 forms a key for holding the cap in place while allowingi-t to revolve, and in addition thereto the screw forms a means for fastening the cap fixedly on the journal 10, so as to prevent relative rotation between the cap and screw.

In order to impart rotary motion to the outer screw 4, I employ a ratchet-collar 14, the outer surface of which is provided with ratchet-teeth 15, as shown, the collar being held in place by suitable fasteners, preferably in the form of screws 16, which are inserted through threaded openings in the collar 14 into sockets 17in the screw 4, as shown clearly in Fig. 2. Associated with the ratchetcollar 14 is an operating-lever comprising a handle 18, of any suitable length, upon the end of which is fitted a metal sleeve 19, containing within it an annular flange 20', forming a guide for a plunger pin or stem and also a spring-rest. Housed within the sleeve 19 is a double-ended dog 21, having two engaging portions 22, either of which may be thrown into engagement with the ratchet-collar 14. At its rear end the dog21 is provided with reversely-inclined surfaces 23, with which 00- operate the corresponding reversely-inclined surfaces 24 of a plunger 25. The plunger 25 is mounted to reciprocate longitudinally within the sleeve 19 and has a stem 26, which plays through the guide-flange 20. An expansive coil-spring 27 surrounds the stem 26 and is interposed between the flange 20 and the enlarged head of the plunger, as shown in Fig. 3, the tension of said spring being exerted to force the plunger toward the dog.

The lever is connected with the outer screw by means of a pair of collars 28, which are spaced apart, as illustrated in Figs. 1 and 2, so as to embrace the ratchet-collar 14 on opposite sides. The collars 28 are preferably .formed as integral parts of the sleeve 19, the

latter being fitted upon the handle 18 in any convenient manner. The dog 21 is provided intermediate its engaging portions 22 with an opening for the reception of a taper pin 29, which forms the pivot upon which the dog 21 may be oscillated for the purpose of throwing one end or the other thereof into engagement with the ratchet-collar14, and thereby adapting the screw to be turned in either direction.

One of the principal features of the present invention resides in a clamp-collar 30, which is split at one side and provided at its extremities with radiallyprojecting ears 31, which receive a thumb-screw 32 for the purpose of jamming the collar on the inner and outer screws 6 and-4. The upper portion of the clam p-collar 30 is internally screw-threaded, as shown at 33, for the purpose of engaging the inner screw just above the upper end ofthe outer or lower screw, as shown in Fig. The lower portion of the clamp-collar is provided with an annular flange or rib 34, which enters a correspondingly-formed annular groove 35 in the outer surface of the upper end of the outer screw 4. This establishes a swiveled engagement between the clamp-collar and lower or outer screw and serves to hold the clamp-collar in position either when loose or tight. When the thumbscrew 32 is tightened, the threaded portion 33 of the clamp-collar binds upon the threads of the inner screw 6 and locks the two screws together by reason of the flange 34: simultaneously binding within the groove 35 of the other screw. The threads within the clampcollar are given a pitch corresponding when the clamp-collar is loosened with the pitch of the threads on the inner screw 6. Therefore when the clamp-collar is tightened the pitch of the threads in said collaris changed sufficiently to cause a binding action between said threads and the threads of the inner screw, and in this way the two screws are locked against relative rotative movement by means of the clamp-collar 30.

From the foregoing description it will be understood that one or both screws may be used, according to conditions. By loosening the clamp-collar 30 and operating the lever 18 a double feed is obtained by reason of the fact that both screws are free to operate. By tightening the clamp-collar and operating the lever 18 only the lower or outer screw is brought into action, while by turning the head 7 by means of a suitable operating bar or rod associated with the lugs 8 the upper or inner screwonly is acted upon. By reversing the dog 21 the jack is caused to elevate or lower, as the case may be, the spring-pressed plunger serving to hold the dog in either position to which it is adjusted.

It will of course be understood that the several parts of the jack are susceptible of changes in the form, proportion, and the minor details of construction, which may ac-- cordingly be resorted to Without departing from the principle or sacrificing any of the advantages of this invention.

Having thus described the invention, what is claimed, and desired to be secured by Let ters Patent, is

1. In a screw-jack, the combination with a supporting-casing and a plurality of screws nested one Within the other and mounted in the casing; pawl-and-ratchet engagement with one of the screws, and a clamp-collar surrounding the adjacent screws and adapted when tightened to lock the screws together for simultaneous rotation.

2. In a screw-jack, the combination with a supporting-casing,and a pair of screws nested Within each other and mounted in the casing; of an operating-lever having a pawl-andratchet engagement with one of the screws, and a clamp-collar having a swiveled engagement with the end portion of one screw and a threaded engagement with the other screw, substantially as and for the purpose specified.

3. In a screw-jack, the combination with a supporting-casing,and a pail-of screws nested one within the other and mounted in the casing; of'an operating-lever having apawl-andratchet engagement with one of the screws, and a clamp-collar having a swiveled engage ment with one screw and a threaded engagement with the other screw, the threads of the clamp-collar corresponding in pitch (when said collar is loose) to the threads of the screw with which it engages.

In testimony whereof I affix my signature in presence of two witnesses.

ROBERT S. BERGER.

Witnesses:

F. F. HINMAN, L. G. WILLSON.

of an operating-lever having a 

